Fighting Fire with Fire: Can Traditional Native American Burning Practices Help Reduce Devastating Wildfires and Increase Soil Carbon Storage?

Project Overview

California's wildfires have become dramatically larger and more destructive over the last few decades, a situation which is in part due to climate warming and drying, making fuels more likely to burn and for a longer part of the year. However, a major factor is also the suppression of fire on the landscape over the last 150 - 200 years, in particular the frequent low-intensity burning used by California's indigenous peoples since time immemorial. In this project, we sought to quantify the effects of high-intensity and low-intensity fire on the amount and forms of carbon stored in soils, building on previous connections to the Karuk Tribe and their active work to return good fire to their aboriginal homelands in the Klamath Mountains.

In collaboration with the Karuk Tribe Department of Natural Resources, we sampled the top meter of soil on four sites recently affected by i) high-intensity wildfire, ii) high-frequency and iii) low-frequency low-intensity burning, and iv) fire suppression (no fire in >100 years). We also interviewed Karuk cultural practitioners and others to understand the history and effects of traditional burning on the soils and landscape. Soils were characterized using stable carbon- and nitrogen- isotope analysis, radiocarbon content, texture and chemistry, and the radiocarbon age of charcoal fragments. In addition, incubation of surface and deep soils and pre- and post-incubation characterization by Nuclear Magnetic Resonance (NMR) explored the effects of different types of fire on the soil microbial communities in the sites.

Mission Impact

This project directly addresses the Climate Impacts and Resilience Mission Focus Area goal to mitigate the accumulation of greenhouse gases in the atmosphere, exploring the potential power of cultural burning to increase soil carbon storage in soil, the largest terrestrial sink of CO2 from the atmosphere. The project supports the Laboratory's Core Competencies in Earth and Atmospheric Sciences, and Nuclear, Chemical and Isotopic Sciences, especially bringing together expertise in soil-carbon cycling, paleoclimate, and molecular analysis. Our collaboration with the Karuk Tribe and the participation of a Native student for both summers directly contribute to Lawrence Livermore National Laboratory's commitment to diversity and inclusion.

Publications, Presentations, and Patents

Shawn A. Pedron, K.C. Moreland, K.D. Ray, S. Bourque, and S. R. H. Zimmerman, "Fighting Fire with Fire: Can traditional Native American burning practices help reduce devastating wildfires and increase soil carbon storage?" (Poster Presentation, Pacific Climate Workshop, Pacific Grove, CA, March 1, 2023).

Kimber C. Moreland and Susan R.H. Zimmerman, "Fighting Fire with Fire: Can traditional Native American burning practices help reduce devastating wildfires and increase soil carbon storage?" (Presentation, Nuclear Energy Tribal Working Group, LLNL, Livermore, CA, June 27, 2023).

Susan R.H. Zimmerman, "Fighting Fire with Fire: Effects of fire intensity and fire frequency on soil carbon" (Presentation, Dept of Geology, Cal State Polytech U, Humboldt, Arcata CA, April 28, 2023).

Randy Pico and Susan Zimmerman for LLNL and the Karuk Tribe DNR, "Fighting Fire with Fire: Can traditional Native American burning practices help reduce devastating wildfires and increase soil carbon storage?" (Presentation, American Indian Science and Engineering Society Annual Meeting, Spokane WA, October 19, 2023).